Schulze and Steiger isolated arginine from etiolated lupin seedlings in 1886. For most of the century that followed it was a building block and nothing more. Then the vessel got involved.
A gas nobody expected
In the 1980s, Robert Furchgott found that the lining of a blood vessel released something that relaxed the muscle around it. The something was nitric oxide. Arginine is the substrate. Ignarro, Murad, Furchgott: the Nobel in 1998, for a gas that lasts seconds and opens a vessel. The gym heard "pump". The older job is simpler: blood flow.
What we ask of it
Swallow arginine and the gut's arginase takes a share before it arrives. The trials that show an effect on erections use grams, not milligrams. So we do not pretend 250 milligrams is a prescription. It sits in XUFU Original beside 1,500 milligrams of L-Citrulline and horny goat weed.
Nitric oxide is not a vitamin. It is a signal. Arginine is how we feed that signal without pretending a capsule is a prescription.
Why it sits in XUFU Original
The current formula uses 250 milligrams of free-base L-Arginine beside 1,500 milligrams of L-Citrulline. Arginine is the plain, unglamorous part of that brief. Not a plant with a legend. A substrate with a Nobel.
This journal will keep one plate at a time. History first. The formula second. Claims last, and only the ones we can stand behind.
End of plate V.